Earthmoving equipment is used to perform a variety of operations, including loading, or capturing, material, such as soil, at one location and dumping, or depositing, the material at another location. For example, such material movement may be employed to adjust elevations at a project site. Scrapers, which typically provide quick load, dump, and maneuver time, may be used to perform such operations, and generally include a machine having a bowl within which the material may be captured, and a cutting edge located adjacent a cut opening of the bowl. Although various scraper configurations are available, scrapers are often pulled by a tractor, such as a wheeled or track type tractor. In addition, scrapers may provide their own traction via a separate engine that applies rim pull, or power, to the wheels of the scraper. In either arrangement, scrapers may also be pushed or pulled by a separate machine, or tractor, to provide additional power for scraper operations.
During a typical operation, or duty cycle, the scraper may be pulled forward, at a material capturing location, while the cutting edge of the bowl is pivoted downward to cut through the material. The cutting edge, oriented perpendicular to the direction of travel, may also serve to guide the material into the bowl. When the bowl is loaded to some desired capacity, the cutting edge of the bowl may be pivoted upward so that the cutting edge is out of contact with the material, and the machine may be transported to a location where the soil is to be deposited. After the material is deposited, often with the assistance of an ejector mechanism, the scraper may be returned to the material capturing location, and the duty cycle may be repeated.
Often, there is a desire to provide a level cut with the cutting edge of the scraper. However, if the bowl of the scraper is loaded unevenly, a side of the bowl may be weighted more heavily, which may result in an uneven cut. Operating across a path having various topographical changes may cause the left or right set of wheels to operate at an elevated level relative to the other set of wheels, which may also result in an uneven cut. To improve cutting in these situations, the cutting edge may be adjusted toward a parallel position relative to the material. According to one example, as shown in U.S. Pat. No. 5,561,924, one of the wheel hubs, supporting left and right wheels on eccentric spindles, may be rotated slightly to tilt the bowl of the scraper and, thus, cutting edge, to reorient the cutting edge relative to the ground. Specifically, a linear actuator, actuated by a motor, is used to independently adjust a rotation of the wheel hubs, through a horizontal displacement, to tilt the bowl and, thus, cutting edge relative to the ground. Although this arrangement may provide more even cutting, it should be appreciated that there is also a continuing need to improve efficiency of scraper operations by reducing the energy required to fill the bowl to its desired capacity.
The present disclosure is directed to one or more of the problems set forth above.